1. Field of the Invention
The present invention relates to a wake-up system adopted to wireless transmission/reception devices such as remote controllers, mobile communication terminals, etc., and more particularly to a wake-up system with passive correlators capable of reducing consumption power for a wake-up operation in a receiver such that correlation operations of a correlator including passive electrical elements such as a matched filter etc. are performed at a transmitter and the receiver in the same fashion and wake-up signals are transformed into signals for performing the wake-up operation in the receiver.
2. Description of the Related Art
Generally, with increase of utility of wireless access communication, a connection network of a type of wired and wireless integrating system is constructed in various fields and thusly there has arisen a demand for a technical standard for low speed, low-priced and low-power wireless communication.
One of low power operating methods is to operate a system in a power saving mode wherein the system in a sleep mode is awakened according to a wake-up signal. In order to perform a wake-up operation according to a wake-up signal, a system should periodically operate and check whether the wake-up signal is received. Also, if the wake-up signal is received, the system should further confirm whether the wake-up signal corresponds to a signal to activate itself.
As such, in order to perform a confirmation operation of the system wake-up, since a plurality of active elements and circuits should be operated, the system consumes a relatively large amount of power, which should be reduced.
With reference to FIG. 1, one of the wake-up systems of a wireless transmission/reception device is described in detail below.
FIG. 1 is a construction view illustrating a wake-up system of a wireless transmission/reception device according to the prior art.
As shown in FIG. 1, the wake-up system includes a transmission controlling unit 10 for controlling wake-up operations of a receiver, a transmission processing unit 20 for generating and transmitting a wake-up signal according to the control of the transmission controlling unit 10, a reception controlling unit 40 for confirming whether its own wake-up signal is received by repeatedly performing conversion operations between a sleep mode and a standby mode, and controlling a wake-up operation of the system if the received wake-up signal is determined to be a signal corresponding to activate itself, and a reception processing unit 30 for receiving and processing a received signal according to the control of the reception controlling unit 40 and providing the processed signal to the reception controlling unit 40.
In a wake-up operation of such a wireless transmission/reception device, when the transmission controlling unit 10 controls transmission of a wake-up signal, the transmission processing unit 20 generates the wake-up signal and transmits it through the air.
Here, when the reception controlling unit 40 is changed from sleep mode to standby mode to control confirmation of a wake-up signal, a signal received by the reception processing unit 30 is amplified, filtered and decoded. After that, it is confirmed whether the received signal corresponds to its own wake-up signal. If the received signal is its own wake-up signal, the reception controlling unit 40 is awakened. Meanwhile if it is not, the reception controlling unit 40 is changed from standby mode to sleep mode.
As such, the wake-up system of the wireless transmission/reception device according to the prior art consumes a relatively large amount of power to be awakened as active elements or circuits such as a mixer or an oscillator must be operated to process received signals based on signal processes such as decoding etc.